Celebrities stumping for charities went from being a good use of excess fame to standard operating procedure, and a tool for PR flaks to use when naughty clients need to make penance. The public has gotten wise and grown bored. So when Ben Affleck and Matt Damon wanted to raise money for their pet causes, they really upped the ante.

Affleck’s East Congo Initiative benefits organizations in that war-torn area. Damon’s Water.Org is on a mission to provide clean water around the world. Both worthy causes, but in a sea of celebs asking for donations for equally good causes, how to gain attention, and dollars? With a contest, and a series of hilarious videos to promote it.

Visitors to Omaze.com can enter the contest for $10. The prize is a trip to Los Angeles for a double date with Affleck and Damon at a Hollywood event, and a stay in a four-star hotel (presumably without the two married Academy Award winners). The promotional videos are the two old friends taking potshots at each other. “You could learn about…how incredibly short Matt Damon is,” says a smiling Affleck. “Or the fact that Ben’s left eye twitches every time you say the word ‘Gigli’,” Damon retorts, referring to Affleck’s bomb with then girlfriend Jennifer Lopez. The videos alone are worth the donation.

THE PR TAKEAWAY: In a crowded room, find a way to stand apart. Clearly, both actors’ causes are worthy, but a world confronted with a steady stream of bad news can’t bear more sad details that usually tug heartstrings and loosen pursestrings. Humor goes a long way, as does clever incentive. A reasonable donation of ten bucks buys a chance at a dream trip with a pair of famous, and obviously fun, actors: pure PR genius.